In a counterintuitive new study, researchers have found that obese women get less pleasure from drinking a chocolate milkshake than average-weight women, and suggest that obese women are therefore more likely to overeat in an attempt to get that high. Researchers used a fMRI brain scanner to record women’s levels of the pleasure-providing brain chemical dopamine while they were sipping milkshakes, and found that obese women had a muted pleasure response.
They also studied a dopamine-regulating gene variant that has previously been linked to obesity, and showed that women with this variant had the lowest dopamine levels and were also very likely to gain weight over the ensuing year. Dopamine expert Nora Volkow says this furthers the research on the genetic component of obesity: “It takes the gene associated with greater vulnerability for obesity and asks the question why. What is it doing to the way the brain is functioning that would make a person more vulnerable to compulsively eat food and become obese?” [AP]
Lead researcher Eric Stice says that the study, published in Science [subscription required], brings up the possibility that some people are born with a vulnerability to obesity, while others eat their way to an unsatisfying addiction. “Probably this is related to downregulation of the brain’s reward circuit. The more you do things that are rewarding, the less reward you see,” Stice says. “The more you eat an unhealthy diet, the more you see this blunted pleasure response to high-energy foods” [WebMD].
Experts say the findings compliment a recent theory that obesity is akin to drug addiction, in which dopamine also plays an important role. “This research follows what we have seen in addictive people,” says Nora Volkow, director of the National Institute on Drug Abuse. “At first we thought they were more sensitive to pleasurable responses. But research has shown exactly the opposite, that they have a blunted response to drugs and release much less dopamine. With obesity, it took everyone by surprise” [Newsweek].
Related Content:
DISCOVER: Is Overeating an Addiction?
DISCOVER: The Biology of Appetite
Image: flickr/nayrb7
October 18th, 2008 at 8:20 am
I’m no scientist but could the lowered response in the brains of the obese young women be a conditioned one? It is commonly known that alcoholics and drug addicts require more and more of what they are addicted to in order to maintain the high that they seek. Could this not also be true of obese people? If obese people are addicted to the pleasure eating food brings, wouldn’t they, like the alcoholic and drug addict, need more and more of it to achieve the same high? Wouldn’t we expect a young woman who had never had a bourbon and Coke to respond more powerfully to it than a young woman who is an alcoholic?
October 20th, 2008 at 3:48 am
Then again, you think that it just might be that big beauiful people may just have other issues that make them turn to food and not an addiction. Like maybe depression or trauma that caused the weight to build. The experts on these colums needs to look at some other prospects too not just that all big people turn to food for the high, or that they overeat cause they cant control it like the addiction process of drugs/alcohol does. There are other aspects involved. Check those out first! This kind of topics are upsetting when these experts think they know it all and they really dont know the client at all. Talk to the source the Big Beautiful Peaople who have the problems……
March 4th, 2010 at 10:19 am
Big people are not beautiful. They are unhealthy – which is what we’re supposed to avoid in a mate. So, stop kidding yourself. Fat people don’t need a pat on the head and another cookie, they need a hard ass making them run that jiggle off.
They get so caught up in self pity that I think it’s fully reasonable to expect them to gobble down food in an effort to finally feel good about something.
March 16th, 2010 at 8:59 pm
Very interesting discover. I have read some similar report: Why some people can get fat easy, but others are not. I think the reason is genetic factors to some extent. And the healthy diet is very important.